Powder actuated setting tools all utilize among other things, a powder charge to set in motion a piston which travels within a barrel. The barrel in one way or another houses a fastener to be forcefully ejected from the setting tool by the piston moving within the barrel. The piston is accelerated by expanding gas in a chamber, that expanding gas being occasioned by the burning of the powder charge. In order for the setting tool to function as intended, the piston must be maintained in a position appropriate to being driven by the expanding gas in the chamber of the setting tool. Effectively, the foregoing means that the piston needs to be held “up” when the setting tool is compressed to a firing position. As is familiar to one of ordinary skill in this art, setting tools of this type generally require compression of the setting tool against work surface before the tool will ignite the powder charge.
The cycle that is relevant to the current disclosure begins after firing the setting tool, the piston being in a “forward” position relative to the setting tool. Upon release of the compressive force applied to the setting tool by an operator thereof, a spring urges the setting tool away from the work surface. As this occurs, the piston is drawn back to a firing position, rearward of the setting tool. The piston must be maintained in this rearward position during the ignition of powder in order to develop the desired linear force due to gas expansion.
The problem arises when the setting tool is again compressed toward a work surface to dispense another fastener. Upon compression, in many of these tools, the components of the tool that hold the piston rearward of the tool are moved and do not support the piston in the desired rearward position. In such condition, the piston moves forward under gravity and linear force generated by expanding gas of burning powder is reduced. This is of course an undesirable result.
To remedy the forgoing problem, manufacturers have utilized different friction creating devices to hold the piston rearward. To date however, such devices have either been overly complex or have not worked reliably. Therefore the art is still in need of a simple yet effective and reliable configuration capable of maintaining the piston rearward of the setting tool until it is forcefully propelled forwardly of the setting tool pursuant to the ignition of the powder charge.